Differential or double driving-gear.



PATENTED JUNE 14, 1904.

H. AUSTIN. DIFFERENTIAL OR DOUBLE DRIVING GEAR.

APPLICATION TILED NOV. 14, 1902.

N0 MODEL.

Patented June 14, 1904.

PATENT OFFICE.

HERBERT AUSTIN, or ERDINGTON, ENGLAND;

DIFFERENTIAL OR DOUBLE DRIVING-GEAR.

SPECIFICATION forming part of Letters Patent No. 762,674, dated June 14,1904.

Application filed November 14:, 1902. Serial No. 131,321. (No model.)

To aZZ whom, it may concern:

Be it known that I, HERBERT AUSTIN, engineer, a subject of the King ofGreat Britain, residing at Erdington, near Birmingham, England, haveinvented certain new and useful Improvements in Differential or Double-Driving-Gear for Use in Driving Self-Propelled Road-Vehicles, of whichthe following is a specification.

I This invention relates to diiferential or double driving-gear(sometimes 'known as balance-gear) of the type in which the wheels ofthe gear which are upon the driven axles are formed with parallel teethand are geared together through the medium of pinions, which mesh withone another and which themselves mesh, respectively, with the wheelswhich are carried by the'axles. In using differential gear, whether ofthis spurgear type or of the-more ordinary type-that is to say, the typein which bevel-wheels are used for heavy roadvehi clesthe inconvenienceis sometimes experienced that when a vehicle is in soft ground one ofthe driven road-wheels is liable to slip, which prevents the vehiclefrom being driven; and the invention has for its object means by whichthe type of gear in which wheels with parallel teeth are geared togetherin the manner above described may be adapted to be locked at will, sothat the axles must revolvetogether, thereby insuring that the vehiclemay be readily driven over soft ground.

The above objectis accomplished according to this invention in themanner illustrated by the drawings herewith, of which Figure 1 is alongitudinal section taken along the center of the gear, being taken inthe plane indicated by line m m of Fig. 2. Fig. 2 is a transversesection of the gear, taken in the plane indicated by line y 1 of Fig. 1,and shows only the parts which are upon the plane of the section. Fig. 3is a corresponding view to Fig. 2, but is taken in the plane indicatedby line 00 m of Fig. 1. Fig. 4: is a corresponding view to Figs. 2 and3, but is taken in the plane indicated by line y of Fig. 1. Fig. 5 is aView corresponding to Fig. 1, but is taken in the plane indicated-byline .2 z of Fig. 3, as the section would appear when such plane isvertical; and Fig. 6 shows in longitudinal section a modification ofcertain parts of the mechanism. Fig. 7 is a sectional View taken in thesame plane. as Fig. 1 and illustrating another modified construction.

Referring primarily to Figs. 1 to 5, A A are the driven shafts or axlesof the balancegear. These axles are alined and have fixed on theirrespective adjacent and inner ends spur-wheels B and B. The teeth of thewheel B mesh at all times with the teeth of two spur-pinions C C, Fig.3, and the teeth of the wheel B mesh at all times with the teeth of twospur-pinions D D, Fig. 2. The faces of the pinions C C and D D are muchbroader than the faces of the wheels B B, as seen in Figs. 1 and 5, andthe teeth of the pinions C and G mesh, respectively, at all times withthose of the pinions D and D, Fig. 4. The pinions C G D D are mounted inand carriedby a drum or carrier E, which is journaled concentricallywith the axles A A, and this drum is driven from the motor through themedium of suitable sprocket-teeth a on the drum or in' any convenientmanner. The pinions C U do not. mesh with the wheel B, nor do thepinions D D mesh with the wheel B, and thus it will be seen that as thedrum or casing E is rotated the axles A A may revolve at different ratesof speed if a greater resistance is offered to the turning of one ofthem than to the turning of the other, as is well understood inconnection with this class of gear. This very useful result, however, ofthe employment of differential or balance gear with self-propelledroad-vehicles .involves the inconvenience above referred to that in softground one of the driving roadwheels is liable to slip, thus preventingthe driving of the vehicle, and the special purpose of this invention isto enable the gear to be locked at will to prevent either of the axles AA from revolving faster or slower than the other. To effect thispurpose, one of the axles-namely, the axle Ais adapted to be slidendwise within its bearings F F, so that its wheel B may be moved inwardto mesh also with the pinions D D. When the axle A has thus been movedinward, it will be obvious that the two axles A A are locked togetherand will revolve as a single axle. The axle A may be moved inward in anyconvenient mannersuch as through the medium of a groove Z) around theboss of a pinion Gr, sprocket-wheel, or the like, from'which the powerof the axle A is given ed to a driving road-wheel. Both axles A A may ofcourse be adapted to be moved inward, so that the wheel B may mesh withthe pinions D 1) and the wheel B mesh with the pinions C C; but this isnot at all required and would obviously add unnecessary complication.

Fig. 6 shows a modification of the invention, in which the wheel B isrigid with a sleeve (Z, which is slidingly mounted on the axle A. Thesleeve forms the inner journal of the axle and drives the axle through afeather-key e. The sleeve may be slid endwise of the axle through themedium of a groovef' around the outer end thereof to move the wheel Binto and out of engagement with the teeth of the wheels D D in lieu ofmoving the axle A endwise for such purpose.

Fig. 7 illustrates another locking means. In this construction theadjacent or inner ends of the alined axles A and A are provided,respectively, with clutch members 0 and c, which are adapted to engageor interlock when the shaft A is moved in for locking. As the wheels B Bare non-rotativc on the respective axles, it is obviously not importantwhether the clutch members form parts of the said wheels or of theaxles.

In differential or balance gear it is usual to drive the toothed wheelon the inner end of each axle at opposite points around it for the sakeof smoothness of running, and this method is shown in the illustrationsfiled herewith. It will be obvious, however, that only the pinions C andD, (or alternatively the pinions C and D,) which mesh each with one ofthe wheels,respectively,and which mesh together, are really essential,though the double arrangement is greatly preferred.

Having fully described my invention, what I claim, and desire to secureby Letters Patent, is-

1. A differential driving-gear for the purpose specified, having drivenaxles, a rotary carrier journaled concentrically with said axles andembracing their inner ends, means within the carrier through which theaxles are compelled to rotate together, said means being put inoperation by a movement of a part of the gear within such carrier, andmeans for imparting such movement from the exterior of the carrier,substantially as set forth.

2. In a differential driving-gear for the purpose specified, thecombination with the alined driven axles, and spur gearwheels mountednon-rotatively on the adjacent inner ends of the respective axles,of arotary carrier journaled concentrically with said axles and embr cingtheir inner ends, and spur-pinions in saiil carrier through which themotion of the carrier is imparted to the wheels, a part of said gearbeing movable longitudinally within said carrier and the gear havingparts within said carrier which engage when said part thereof is somoved, substantially as set forth.

3. In a differential drivinggear for the purpose specified, thecombination with the :alined driven axles, spur-wheels on the inner,adjacent ends of said axles, and a rotary carrier journaledconcentrically with said jaxles and embracing their inner ends, ofrelagtively broad-faced pinions mounted in said fcarrier and gearingtogether, said pinions also gearing respectively with the said wheels;on the axles, but each pinion gearing normally with only one of saidwheels, and means for putting the wheels on the axles both in gear withthe same pinion, whereby the parts fare interlocked and the axlesprevented from grotating independently, substantially as set forth.

4. In a differential driving-gear for the purpose specified, thecombination with the galined driven axles, the spur-wheels mounted onthe respective inner and adjacent ends of :the axles, and a rotarycarrier journaled concentrically with said axles and embracing theWl1G0lS on the ends of the latter, of broad- ;faced spur-pinions mountedin said carrier I and gearing with each other, one of said pinionsgearing normally with the wheel on one axle and the other normally withthe wheel on the other axle, one of said axles being slidably mounted inits bearings so that it may be moved endwise, whereby the spur-wheel onsaid slidable axle may be made to'gear with both of said pinions andthereby lock the axles against independent rotation, substantially asset forth.

In witness whereof I have hereunto signed my name, this 5th day ofNovember, 1902, in the presence of two subscribing witnesses.

HERBERT AUSTIN.

Witnesses: 7

ROBERT G. GROVES, THOMAS MARSTON.

